Method of and apparatus for selective wireless telegraphy.



F. e. SARGENT. I METHOD OF AND APPARATUS FOR SELECTIVE WIRELESS TELEGR APHY. APPLICATION FILED NOV. 14, 1912.

1,09 1,768,, Patented Mar. 31, 1914.

To all whom it may. concern:

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FREDERICK G. SABGENT, 0F WESIFORI MASSACHUSETTS.

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Be it lmown that l, Frenchmen G. San- :onnr, a citizen of'the United States, resid new and useful Method of and Apparatus for Selective Wireless Telegraphy, of which the following is a specification.

This invention relatesto a system of communicating or telegraphing, and for other purposes particularly adapted for use with wireless apparatus. g

The principal objects. of the invention are to secure secrecy and simplify both the sending and receiving operations.

lhe invention also involves improvements in features of construction and combinations of parts as will appear hereinafter. 3 Reference is to be had to the accompanying drawings in which- Figure 1 is a diagrammatic elevation of a sending station; Fig. 2 is a similar view of a receiving station adapted to coliperate therewith; Fig. 3 is a View of one of the dials showing a modification, and Fig. 4 is a similar View showing another modification. Referring to Figs. 1 and21t Wlll be seen that at each station there are two members one rotary and one stationary; namely a dial l0 and a'pointer or indicator 11. For,

the purpose of this invention either the dial or the pointer may rotate and in the form shown in Figs. 1 and 2 the (halls intended to be stationary and the indicator to rotate.

.The means for rotating the rotatable memher is not shown herein but any well known form ofclock work or other rotating mechanism can be employed. It is intended to have the rotation at the several stations synchronous. h For this pur ose the instruments. can be set or adjusted y the time signals sent out by the wireless stations every day .or they can be provided with extremely accurate instruments so they will keep correct time with each other. At any rate, when commencing to operate, the stations can be simple means.

adjusted to see if they are in unison by any With the parts arranged as solar described, the apparatus can be used with any they can, it necessary, compare their dials Specification of Lettez's'Patent. Pa,{;@med E1341; 3}, 1914 7 Application flied lfifoveznber 14. 1am.- Serial No. new.

I I i v r to see that they are in unison and f not, ad-- just them so that they will be. The several dials, being provided with series of characters arranged in the same orderthereonm and rotatinginthe same direction, or the indicator rotating in the same direction as the case may be; the operators atIthe stations can give a pro-arranged signal, as for example a and if the signal is received 55 at the stations when the indicators and dials are at that point it will be understood that all the instruments are in unison. The send'-" v.ing operator then sends signals by iving any predetermined signal, as a dash 5r dot,

over the apparatus when the indicator 11 ndicates the desired letter or character on his dial. The instruments being in unison and the signal being. sent instantaneously the receiving station-will get the signal wh its indicator is showing the same letter r character. It will be' understoodof' course that ordinarily the same signal willbesent over the wireless apparatus each time so that to any station not having this appara- '30 tus the. communications,from-the sending station would appear to be a repetition of the same signal butat unequal intervals. This system can be used also in actual con nection with the wirelessiapparatus now in 35 use and for this purpose the following connections are shown. On each of the dials 19 there are a series of contacting pins 12001? responding in number with the characters on the dials, and the indicator 1.1 contacts with these periodically as it rotates. In Figs. 1. and 2 the indicator is shown as having a projection 13 fon this purpose and the pin with which this projection is shown in contact in Fig. 1 would represent the character A or 1. From eachof these pins 12 a con-' ductor 1 1- is taken oil which is connected with a push button 15 having a character thereon corresponding with the character which the indicator shows when that'pin 12 is in contact with it; These push buttons 15 thus constitute a key board. Each one is provided with a contact 16 which engages a bar 17 when the key is depressed. This bar is connected with an electrdmagn'et 18 con- 10 nected with a battery 19. This in turn is connected with the metallic case 20 in which the dial is located, which is electrically connected with the shaft 21 with which the metallic indicator 11 rotates. .Consequently as two ever being closed at the same timar The pressing down of any one of the keys 0f the key board closes that circuit at one point and then the circuit-is completed whenever the indicator gets around to the position which indicates the same character. Then the magnet 18 is energized, a contact 22 is made, and a current is set up in the usual rimary 23 and secondary 24:. The circuit in which the secondary circuit 24 is located is' provided with the usual condenser 25, oscillators 26, and aerial 27 The receiving station is shown of a well known type having the aerial 28, coil 29, condenser 30 and detector 31. It is also provided with a telephone receiver 32 and this circuit .is connected up with the dial at this station in a manner similar to that described at the other station, but there is no key board. .One end of the circuit is connected withthe case' of the dial/so that it is constantly connected-with the indicator and the other end of the-circuit is' divided into as many lines as there are characters and one connected with each of the pins 12;

It will be understood of course that while i I have described a complete sending station and a: complete receiving station. separate from each other, ordinarily each station will actually be provided with both the receiving. and the sending mechanism. In this case the sending station is connected up for receiving purposes by simply switching outthe battery- 19 and connecting these Wires to a-telephone circuit located as at whatl have called the sending station. In either case the telephone circuit-is closed only when the dial and indicator are in the same relative position as that in which they are in at the sending station. At other times nothing can be heard on the telephone receiver as its connections are broken. It will be understood, of course, also that the telephone receiver can be dispensed with and a coherer used in the ordinary way for.

operating the relay. The relay then can operate lights or other apparatus for signals or other desired kind of communication or purposes. It will he understood, of course, also that the clock mechanism for operating the dials or indicator can he made to run only for a definite period of time if desired before requiring'rewinding, or that the same can be made on the same principle as a stop watch so that it can be stopped and started as desired'to'save some of the rewinding. With a stop watch arrangement it can be arranged to start always on a definite char acter and then the device canbe' employed to place the several-stations in unison: It will be understood of course that the clock work can be re dial can be. ma e to revolve at an eoav' i'ent sgeed, depending upon 'thefsizeithei eo and t e distanceapartlei thejeharactsrs lated so that the hand on In Fig. 3 another construction is shown I in which the dial 35 rotates and is provided with a cover 36 having openings' 37 therethrough constituting an indicatqr sothat it will be simpler for the-'operator'to tell which character is in',the position for communication. The keys and contacts are used as in Fig. 1. In Fig. i another similar construction is shown'in-which there is a relative rotation between the dial 38 and the cover 39, a space 40 being provided for the purpose of designating the position of the letter called. Thisis merely an indicator without electrical connections Whether connected up as described or usedsimplyfi as a selective signaling device without'the eleconly a few modifications of the invention,

I am aware of the fact that other changes can be made therein'by'any person skilled .-in the art .without departing from the scope of the invention as expressedin the claims. Therefore, I do not wish to be limited to all the details herein shown and described, but

What I.do claim is "1. The improvement in the art of sending I messages, which consists in'synchronously and continuously,' but independently; re- Y volving indicators relatively to similar dials having characters thereon arranged in the same way at the sendingand receiving sta tions respectively, sending a signal from the sending to the receiving station at the instant that the indicator shows a desired character on the dial at the sending station,

whereby the operator at the receiving station will determine the character intendedto be sent by noting what character on his dial is' findicated by his indicator when he receives the signal. v p I 2. The improvement inthe art of wireless telegraphy which consists in synchronously I and continuously revolving pointersrelatively to similar dials having characters thereon arranged in the same way at. the

sending and receiving stations respectively, I

sending 'a signal by wireless means from the sending stant that the indicator shows a desired character on the dial at the sending station,

whereby the operator at the receiving sta-,

to the receiving station at the iii-,n

tion will determine the character intended to be sent by noting what character on his dial is indicated by his indicator when he receives the signal.

3.111 a wireless tele aph apparatus; the.

tailing. said d5 ale indieatorsht "conibinationof a set 0 dials and indicators .therei'or, one at each station, means forma 1,!

" and continuously, each dial being provided with a series of characters arranged thereon I connected with said contacts, means for clos- 'lrey is lowered a circuit to the sending apand indicators, one at each station, means tion relatively to each other, synchronously in the same order, a series of contacts corresponding one with each character, circuits ing each circuit when the indicator of that dial indicates the character corresponding to'the contact connected with that circuit, and wireless-telegraph apparatus connected with said circuits.

i, In a wireless telegraph or signaling apparatus the combination of a set of, dials and indicators, one at each station, means for relatively rotatin the dial and indicator of each station sync ronously with the rotation of those of the other station or stations, each dial being provided with a series of characters arranged thereon in the same order at the several stations and with a series of contacts corresponding with said characters, means for engaging said contacts in the same order at the several stations as the rotation is carried on, circuits connected with said contacts, a key-board atthe sending station having keys, one connected with each of said circuits, each key correspondin with one or the characters on the dial, a wireless sending apparatus, and means whereby when any paratus will be com leted with the exception of the making oi t e contact at the dial.

5. In a wireless telegraph or signaling, apparatus, the combination of a set of dials for relatively rotating the dial and indicator of each station synchronously with the rotation of those at the other station or stations, each dial being provided with a series of characters arranged thereon in the same order at the several stations and with a series of contacts corresponding with said characters, means for engaging said, contacts in the same order at the several stations as the rotation is carried on, circuits connected with said contacts, a key-board at the sending station having keys, one connected with each of said circuits, each key corresponding with one of the characters on the dial, a wirel s sending apparatus, means whereby when any key is lowered a circuit to the sending apparatus will be completed with the exception of the making of the contact at the dial,

a corresponding number of partial circuits at the receiving station each adapted to be closed by the relative rotation of the dial and indicator in the same order as at the sendin station, and means in series with all of sai partial circuits at the receiving stab tion for detecting the sending of a signal.

6. In a wireless telegraph or signaling apgaratus, the combination of a set of dials an indicators, one at each station, means for relatively rotating the dial and indicator of each station synchronously with the rotation of those of the other station or stations, each dial being provided with a series of characters arranged thereon in the Same; order at the severalstations and with a series of contacts corresponding with said characters, means for engaging said contacts in the same order at the several stations as the rotation is carried on, circuits connected with said contacts, and a key-board at the sending station having keys, one connected as with each of said circuits. In testimony whereof I have hereunto set my hand, in the presence of two subscribing wltnesses.

FREDERICK G. SARGENT. 

